During start-up of circuits of an apparatus, it is many times not feasible to start them all at the same time. The reason can be that an electrical power source of the apparatus is not able to supply enough current, or that some parts or the circuitry needs other parts to be up and running for proper start-up.
EP 1890220 A2 discloses a power sequencing circuit which allows sequenced start-up of power supplies. The switching of the sequencer is controlled by a fixed delay between each output switching on. The timing is controlled by an external component to adjust the switching interval. External capacitors and/or resistors are used to determine the switching interval.
However, there is a desire to provide an alternative solution which provides a flexible and low-cost start-up approach.